Chapter 106 

Clinical Aspects of and Therapy for Hemophilia A

Doreen B. Brettler, Elissa M. Kraus, and Peter H. Levine


Hemophilia A, the most common of the true hemophilias, accounts for
approximately 85% of cases. It is an X-linked recessive bleeding
disorder attributable to decreased plasma levels of properly functioning
factor VIII (also known as antihemophilic factor).

Probably originally named haemorrhaphilia, the disease was referred to
as hemophilia by Schnlein in the early 1800s. 1 In 1893, Wright 2 noted
that blood from patients with hemophilia demonstrated a prolonged
clotting time. In 1911, Addis 3 showed that the latter could be
corrected in vitro by adding normal plasma. In 1947, both Brinkhous4 and
Quick 5 independently suggested a role for factor VIII in the generation
of plasma thromboplastic activity. That same year, Pavlovsky 6 correctly
inferred the presence of multiple types of hemophilia by showing that he
could correct the clotting defect in certain hemophilic plasma samples
by adding plasma from certain other hemophilic donors.

Lane 7 successfully transfused a patient with hemophilia in 1840, and
plasma was first used as therapy in 1923 by Feisly. 8 Due to the minute
quantities of factor VIII in plasma, its short half-life, and problems
of circulatory volume overload, the vast majority of persons with
hemophilia succumbed to hemorrhage early in life during the era of whole
blood plasma therapy. In one study from Scandinavia, 9 for example, the
mean age of death between the years 1950 and 1959 was 10.2 years for all
persons with hemophilia.

In 1964 Pool et al. 10 analyzed the content of the annoying precipitate
that formed transiently during the thawing of fresh frozen plasma and
found it to contain a disproportionately high amount of factor VIII.
Thus, the era of cryoprecipitate therapy began, and this treatment made
the first meaningful improvement in life expectancy. For example, in the
same Scandinavian study, 9 the average age at death between 1960 and
1969 doubled to 20.1 years.

The late 1960s saw the introduction of partially purified preparations
of factor VIII, prepared by glycine precipitation of fresh plasma and
later by polyethylene glycol precipitation. 11 More recently,
therapeutic products highly purified from human plasma by the use of
immunoaffinity chromatography have been available. MLID88264487  12 The
first infusion of recombinant factor VIII was reported by White and
colleagues in 1988. 13 Subsequently, >100 patients have been studied,
all of whom have received recombinant factor VIII without difficulty.
MLID91061845  14


Both Hemophilia A and B were studied by the National Heart, Lung, and
Blood Institute in 1972. 15 Their estimate of incidence was 25 cases per
100,000 males. Other studies have suggested lower figures, and most
experts believe the correct figure to be approximately 20 cases per
100,000 males (1 per 10,000 of the whole population), with factor VIII
deficiency accounting for 85% of these. Factor IX deficiency explains
14%, and the remaining cases involve the rare congenital clotting factor
factor XI, X, VII, or V deficiencies. There is no reason to believe that
the incidence of hemophilia varies in different races or by geographic
areas of the world.

Among patients with hemophilia A being treated in the United States, 60%
are classified as severe (i.e., have a factor VIII level of <1% of
normal). Most of the remainder have moderate disease (factor VIII level
>1% of normal). The number of people with mild disease is not known, as
many such patients undoubtedly are mild bleeders and escape detection.

Clinical Severity

The frequency and severity of bleeding in hemophilia may be predicted
from the factor VIII procoagulant level, assayed in comparison to a
reference standard that is assumed to have factor VIII levels of 100%,
corresponding to a factor VIII activity of 1.0 U/ml. The factor VIII
level in normal persons ranges from 50% to 200% (0.502.0 U/ml). Those
with factor VIII levels F1% of normal (F0.01 U/ml) have hemorrhages
requiring therapy two to four times monthly on the average, although the
range is large and the episodes are irregularly spaced. Such patients
are classified as severe hemophiliacs. Those with factor VIII levels >5%
of normal (>0.05 U/ml) are considered mild hemophiliacs and usually
hemorrhage only due to trauma or surgery. Some such cases are not
diagnosed until adult life. Occasional spontaneous hemarthrosis may
occur in such patients, especially in joints damaged by previously
undertreated post-traumatic hemorrhage. Patients whose factor VIII
levels are between these two ranges are considered moderately severe,
and their clinical picture falls between the two extremes. If such
patients have had multiple untreated, or suboptimally treated
hemarthroses with subsequent joint damage, the anatomic instability of
these joints will cause frequent and severe bleeding, and the disease
will therefore appear clinically more severe than the factor VIII assay
would suggest.

The choice of treatment for factor VIII deficiency depends on its
severity. Those with severe or moderate disease are treated with factor
concentrate. Patients with mild disease (factor VIII levels >10%) can
receive desmopressin (deamino-D-arginine vasopressin [DDAVP]).
Cryoprecipitate is also used in some centers to treat mild hemophilia A.
However, since it cannot be virally inactivated, most physicians use
factor concentrate in patients with mild hemophilia A who do not respond

Within a given hemophilia kindred, the clinical and laboratory severity
of the disorder is relatively consistent. The appearance of a more
severe clinical course in a family relative should raise the question of
either established anatomic lesions that predispose to frequent or
severe hemorrhage, or the development of an inhibitor.

Clinical Manifestations

The clinical hallmarks of hemophilia A are (1) lack of excessive
hemorrhage from minor cuts or abrasions due to the normalcy of platelet
function; (2) joint and muscle hemorrhages, which lead to the most
difficult and disabling long-term sequelae; (3) easy bruising; (4)
prolonged and potentially fatal postoperative hemorrhage; and (5) a
panoply of social psychologic, vocational, and economic problems. For
many patients treated with blood products prior to 1985, acquisition of
human immunodeficiency virus (HIV) exacerbated already severe clinical
problems. MLID87239713  16 Finally, slowly progressive hepatocellular
disease, mainly attributable to chronic hepatitis C, remains a threat to
patients. 17


The joints most frequently involved (in descending order of frequency)
are the knees, elbows, ankles, shoulders, hips, and wrists. Bleeding
into the hand is rare and usually follows significant trauma, while the
spine is rarely, if ever, involved.

The first episodes of acute hemarthrosis occur in childhood, but often
not until the child begins to walk. Infants and small children may
develop large ecchymoses from being carried or lifted. Hemarthrosis is
usually either spontaneous or associated with imperceptible trauma. The
onset of hemorrhage is signaled by an "aura," consisting of vague
warmth, a tingling sensation, and/or a sense of mild restlessness or
anxiety; this aura may last up to 2 hours. Mild discomfort and slight
limitation of joint motion occur next, followed (after 1 to several
hours) by pain, joint swelling, cutaneous warmth, and eventual severe
limitation of motion. Once bleeding has stopped, the blood is
reabsorbed, and the joint returns to normal over several days to several

When pain, swelling, and severe limitation of motion are present, the
hemorrhage is far advanced and the process of synovitis begins; this may
predispose the joint to further episodes of hemarthrosis and to
hemophilic arthropathy 18 (Fig. 106-1). Joint hemorrhage should be
treated after the earliest symptoms are noted and before any physician
findings to prevent the long-term disabling sequelae. Adults may
demonstrate periodic joint pain due to established hemophilic
arthropathy rather than bleeding and may have considerable fibrosis of
the joint capsule, thus preventing joint swelling. They may develop
chronic limitation of motion, removing the value of this finding in
diagnosing an acute bleed. Prophylactic correction of the hemostatic
defect over several weeks or months can help the patient to
differentiate acute hemarthrosis from the background of chronic symptoms
and signs.

An episode of bleeding into a joint predisposes to further episodes for
at least two possible reasons. MLID75088474  19 First, hemarthrosis
stimulates proliferation, chronic inflammation, and hypervascularity of
the synovial membrane. Second, hemarthrosis is accompanied by rapid
atrophy of the periarticular musculature and a subsequent compromise in
joint protection exerted by these muscles (Fig. 106-2).

Chronic Arthritis

Recurrent hemarthrosis may lead to a self-perpetuating condition in
which joint abnormalities persist in intervals between bleeding
episodes. Clinically, the involved joint is chronically swollen,
although painless and slightly warm. There are clinical findings of
chronic synovitis, including prominent synovial bogginess with or
without effusion (Fig. 106-3). Mild limitation of motion may be present,
often with flexion deformity. Factor replacement does not modify these
parameters. The likelihood of developing chronic arthritis is directly
related to the overall severity of the underlying coagulation defect. In
one study of 139 hemophiliac patients, only 42% were found to have
definite and an additional 14% possible hemophilic arthritis, based on
clinical and radiographic features. 20 Despite any previous history of
hemarthrosis, however, no patient with a factor level >20% had
hemophilic arthritis, while up to one-third with levels between 6% and
20% had possible or definite arthritis. In those patients who develop
chronic arthritis, it is not clear whether the phenomenon is due to
repeated subclinical minor hemorrhage or to irreversible synovial
proliferation induced by major hemarthroses. However, it is this
clinical state that often progresses to the severe destructive arthritis
seen in advanced hemophilic arthropathy. The radiologic changes are seen
in Figures 106-4 and 106-5. Nonsteroidal anti-inflammatory agents have
been found to offer significant pain relief without routinely causing
increased bleeding difficulties.

End-Stage Hemophilic Arthropathy

Long-standing end-stage hemophilic arthropathy has features in common
with both degenerative joint disease and advanced rheumatoid arthritis.
18 The radiographic changes are shown in Figures 106-6 and 106-7.
Clinically, the joint appears enlarged and "knobby," due to osteophytic
bony overgrowth (Fig. 106-2). Synovial thickening and effusion, however,
are not prominent. Range of motion is severely restricted, and fibrous,
in contrast to bony, ankylosis is frequently seen. Subluxation, joint
laxity, and malalignment are common. Hemarthroses, however, decrease in

Septic Arthritis

Although many diseases such as rheumatoid arthritis and osteoarthritis
confer an increased risk of bacterial infection of a previously damaged
joint, septic arthritis is a rarely reported complication of hemophilic
arthritis. Pyogenic arthritis in hemophiliacs more commonly occurs in
adults than in children and is usually monarticular, with a predilection
for knee involvement. Compared with spontaneous hemarthrosis, septic
arthritis is associated with a fever >38C within 12 hours of
presentation, an increased peripheral leukocyte count, and articular
pain that does not improve with replacement therapy. A predisposing
factor other than hemophilic arthrop- athy is often identifiable,
including previous arthrocentesis, arthroplasty, intravenous drug usage,
or immunosuppression secondary to HIV-1 infection. Staphylococcus aureus
is the most frequently identified organism. MLID86153874  21


Small intramuscular hematomas are common and may resolve spontaneously,
but large hematomas may lead to severe sequelae by way of compression of
vital structures. Large hematomas may produce fever, leukocytosis,
severe pain, and hyperbilirubinemia due to erythrocyte degradation.
Those not adequately treated may result in fibrous organization with
contractures. A large hematoma of the back and flank is seen in Figures
106-8 and 106-9.

Psoas Hematoma

Hematoma of the psoas muscle or in the muscles of the retroperitoneum
may cause either pain in the lower quadrant of the abdomen (which mimics
appendicitis) or pain referred to the groin (which is mistaken for
hemarthrosis of the hip.) 22 Distension of the iliopsoas muscle causes
the leg to be held in flexion at the hip, and compression of the femoral
nerve causes pain on the anterior surface of the thigh. Increased
pressure on the femoral nerve leads to paresthesia, hypesthesia,
weakness of the quadriceps muscle, and even permanent paralysis of the
thigh flexors.

Other Closed-Space Hemorrhage

Bleeding into the muscles of the forearm may lead to median or ulnar
nerve paralysis or Volkmann's ischemic contracture of the hand. Calf
lesions may lead to fixed equinovarus deformity at the ankle or to
peroneal or other nerve palsies. Less common is wrist bleeding with
nerve entrapment syndromes. Spontaneous or traumatic bleeding into the
tongue or the muscles or soft tissues of the neck or throat may rapidly
obstruct the airway, thereby requiring prompt and vigorous therapy.

Hemophilic Cysts and Pseudotumors

A large intramuscular hemorrhage may uncommonly result in the formation
of a simple muscle cyst that clinically appears to be an encapsulated
soft tissue area of swelling overlying muscle. Cyst formation in this
setting is confined by the muscular fascial plane and results most
likely from inadequate resorption of blood and clot. Subperiosteal or
intraosseous hemorrhage, by contrast, may lead to a rare skeletal
complication of hemophilia, a hemophilic psuedotumor. 22 Hemophilic
pseudotumors are of two types: (1) the adult type that occurs
proximally, usually in the pelvis or femur, and (2) a childhood type
that occurs distal to the elbows or knees and carries a better prognosis
than the adult type. Conservative early management of both muscle cysts
and psuedotumors is indicated, including immobilization and factor
replacement. If these lesions progress, however, surgical removal is
indicated to avoid serious complications such as spontaneous rupture,
fistula formation, neurologic or vascular entrapment, and fracture of
adjacent bone. MLID77254733  23 Aspiration of a pseudotumor or cyst is
contraindicated. An example of a pseudotumor is seen in Figure 106-10.


Two-thirds of hemophiliacs will have had at least one episode of
hematuria. 24 Most urinary bleeding is painless, but mild flank pain may
be present, and occasionally severe renal colic occurs, the latter often
associated with a clot in the ureter or renal pelvis.

Explanations of such bleeding vary from a trivial cause to significant
underlying renal pathology. Hematuria is treated with increased fluid
intake for several days and rest, followed by factor VIII for 24 days
if the bleeding continues. Use of e-aminocaproic acid should be avoided
because of the risk of preventing the lysis of clots that obstruct the
ureter. Renal ultrasound or other studies are not done unless hematuria
is chronic or recurrent or severe flank pain is present.

Intracranial Bleeding

Intracranial bleeding accounts for 25% of the hemorrhagic deaths in
hemophiliacs. Antecedent trauma has occurred in one-half of such deaths.
Bleeding may be subdural, epidural, subarachnoid, intracerebral, or
(rarely) intraspinal. In one cooperative study of 2,500 hemophiliacs
studied over 10 years, MLID78166239  25 71 episodes of central nervous
system bleeding were documented; the mortality rate was 34%, and 47% of
the survivors were left with mental retardation, seizure disorders, or
motor impairment.

Survivors had been treated with sufficient clotting factor concentration
to raise the factor VIII level to 30%50% of normal for E1014 days.
Current regimens suggest maintaining levels approaching 100%.

Control of Pain in Hemophilia

Pain is an extremely common problem for many  persons with hemophilia.
The two major causes are pain  due to pressure from hemorrhage into
joints, muscles,  or other tissues and chronic arthritis pain, in which 
permanent changes have occurred in the anatomy of the  joints. The
control of pain is a major issue for people  with hemophilia, and
extensive time and energy should  be put into training the patient in
this regard. We believe  that several general rules are important.

Acute joint pain should always be assumed to be due  to bleeding. At the
earliest symptom of joint discomfort  or limitation of motion, the
correct therapy is correction  of the clotting factor defect. Early
application of infusion  therapy prevents pain and long-term joint
clotting factor  defect. Patients who are taught the general philosophy 
when in doubt, infuse will wind up using less clotting  factor
concentrate in the long run than those who adopt  a wait and see
attitude. The latter group will have  advanced lesions requiring
frequent treatment and higher  doses and will also develop chronic
synovitis requiring  many days or weeks of treatment.

Chronic joint pain that fails to respond to infusion of  factor VIII or
IX may sometimes be arthritic pain.  However, this determination should
only be made after an  attempt has been made to correct the coagulation
defect  for a period of days. If the pain that persists is  accompanied
by stiffness and is accentuated early in the day, it is  more likely to
be arthritic than hemorrhagic. In patients  whose pain has hemorrhagic
characteristics and who do  not respond to correction of the coagulation
factor  defect, the use of nonsteroidal anti-inflammatory agents  may
provide considerable benefit. Aspirin must be  avoided because of its
prolonged antiplatelet effect.      A major problem for most patients
with hemophilia  prior to the availability of adequate means of
correcting  the coagulopathy was narcotic addiction. Obviously, the 
non-narcotic agents should be used whenever possible  when analgesics
are required. More than 90% of patients  treated at our center never use
narcotic pain medicines  and control their pain only with infusion
therapy and  the use of acetaminophen. Among older adolescents and 
adults with established hemarthrosis, the use of  nonsteroidal drugs for
arthritic pain is helpful, and at any given  time between one-third and
one-half of our patients in  this age group will be using nonsteroidal
anti-inflamma tory agents.

Patients should be taught that literally hundreds of  medications
available over the counter contain aspirin.  Lists of aspirin-containing
compounds are available from  a variety of sources including the
National Hemophilia  Foundation in New York. Our own general rule is
that  patients with hemophilia take no new medication of any  sort until
they have checked with the center.

Occasionally the relief of chronic pain in hemophilia  will require the
use of alternative therapies, such as an  exercise program administered
by a physical therapist,  biofeedback, acupuncture or acupressure, 
transcutaneous nerve stimulation, or hypnosis. A risk with hypnosis  is
that the patient may neglect to pay attention to  episodes of pain,
which indicate new hemorrhage for which  the patient should be seeking
medical intervention.

In the last analysis the best way to control pain in  hemophilia is to
prevent it through the early and adequate  application of replacement
therapy and through the use  of home infusion incorporated into a
program of patient  education and comprehensive hemophilia care.

Other Sites of Hemorrhage

Gastrointestinal hemorrhages, manifested by hematemesis, melena, or
hematochezia, are unusual in hemophilia. They are usually caused by
organic gastrointestinal lesions.

Prolonged gingival oozing is common after shedding of deciduous teeth,
eruption of new teeth, or instrumentation. If such oozing is
sufficiently prolonged or severe enough to require therapy, several days
of e-aminocaproic acid (Amicar) therapy will usually suffice. Infusion
of coagulation factor is only occasionally needed.

Epistaxis is not unusual in the severe hemophiliac, but it is unusual
for mild hemophiliacs in the absence of a local nasal lesion. It is
largely treated by local measures but may require factor infusion and

Post-traumatic hemorrhage requires a special comment. Normal platelet
plug formation may initially provide good hemostasis but delayed
bleeding usually follows trauma. For this reason, many centers advocate
treatment after significant trauma whether or not evidence of hemorrhage
is yet apparent.


General Considerations

The many ramifications of this lifelong expensive and crippling illness
must be considered or the efficacy of treatment will be impaired and the
outcome will be poor. Hemophilia societies are useful sources of
paramedical support and information. Many problem areas exist, including
the following: (1) interactional difficulties between hemophiliacs and
the health care system 26; (2) psychological sequelae of
overprotectiveness, such as the daredevil syndrome 27; (3) poor
adjustment of the hemophilic child to school 28; (4) the enormous
financial costin the range of $20,000100,000/year for each patient
depending on weight and severity; (5) important vocational problems in
adults with established arthropathy 29; and finally, (6) a low level of
education about hemophilia on the part of health care professionals,
owing to the relative rarity of the disease and the pace of recent
therapeutic advances.

Principles of Replacement Therapy for Factor VIII

The hemostatically effective plasma level for each coagulation factor is
different and depends in part on the nature, extent, and duration of the
bleeding lesion. The dose of replacement factor is calculated in units:
1 U is the activity of a given coagulation factor found in 1 ml of
pooled, citrated fresh frozen human plasma. The factor must be given in
sufficient quantity to allow for its clearance, metabolic half-life, and
volume of distribution with the body.

The half-life of factor VIII in plasma is between 8 and 12 hours, which
includes an initial rapid decline in level owing to diffusion into
extravascular pools. 30 The minimum hemostatic level of factor VIII for
relatively mild hemorrhages is 30% (0.30 U/ml of plasma), while that for
advanced joint or muscle bleeding or for other major hemorrhagic lesions
is 50% (0.50 U/ml). One to several days of maintenance therapy is needed
for such advanced lesions to resolve. Resolution is achieved by
repeating the infusion at 24-hour intervals at approximately 75% of the
original dose. For life-threatening lesions or surgery, levels of
80%100% (0.801.00 U/ml) should be achieved and the factor VIII level
should be kept above the 30%50% range by means of appropriate doses of
factor VIII infused at intervals of 812 hours. 31 This more frequent
infusion regimen decreases the incidence of excessively low levels just
prior to an infusion and also decreases the total amount of factor
needed to maintain given in vivo minimum plasma levels. Constant
infusion regimens are another option when levels need to be maintained
above a set minimum. MLID89333689  32

Doses can be calculated by multiplying the recipient plasma volume in
milliliters by the desired increment of factor VIII in units per
milliliter. A simpler and reproducible dose calculation is that each
unit of factor VIII infused per kilogram of body weight yields a 2% rise
in plasma factor VIII level (i.e., 0.02 U/ml). An example of therapy for
a 50-kg patient with an extensive laceration would include maintenance
of a 30% factor VIII level in vivo until healing is complete. This can
be accomplished by an initial infusion to the 60% level with 1,500 U (30
1 50 kg) of factor VIII, followed by 750 U every 12 hours thereafter for
710 days, with dose adjustments being made every few days as indicated
by factor VIII assays.

For patients with major or life-threatening lesions, the laboratory
measurement of in vivo factor VIII activity is advisable because of
variations that result from the responses of patients to such infusions.
33 Substitution of the activated partial thromboplastin time or another
screening test for a formal factor VIII assay should be avoided because
the results may be misleading.

Antihemophilic factor may be given on a variety of schedules to keep the
amount of in vivo factor VIII above a fixed level, thus converting a
patient with severe deficiency to one with a mild or moderate
deficiency. Prophylactic factor used on a regular basis in small
children is being explored as a method of preventing later costly joint
deterioration. Such a program can dramatically reduce the incidence of
hemorrhages, but it can also increase the expense, the drain on plasma
resources, and possibly the side effects as well. Indications for such
prophylactic use include intensive physical therapy, recurrent
hemorrhage in a single joint or chronic synovitis, or learning a new
physical activity.

Indications For  Infusion 

Guidelines for doses of replacement therapy are  variable from treater
to treater, and there should be room  for upward dose modification when
the clinician is  concerned that lesions are advanced or more
threatening  than usual. Below is a link to a table of typical initial
doses of  replacement therapy used at our hemophilia treatment  center.

Table Table

Other Therapeutic Principles

Acute hemarthrosis should be treated with early infusion therapy, which
will minimize the risk of chronic synovitis or progressive arthropathy
and avoid the need for excessive pain medication or for arthrocentesis.
Aspiration of the joint during an acute hemorrhage should be avoided
unless the swelling and pain are very severe or a septic joint is
suspected. The total consumption of factor concentrate and health care
costs are the same in patients so treated as in those in whom advanced
hemorrhagic lesions develop, and the health of the patient is clearly
improved. MLID75089203  34

Chronic hemophilic arthropathy can improve remarkably from several weeks
or months of intensive physical therapy for muscle building and
increased joint stability, intervals of avoiding weight bearing to allow
for the regression of synovitis, and the correction of flexion
contractures by wedging casts, night splints, or traction. 35 Regular
prophylactic infusions of factor VIII can also be used to prevent
traumatic bleeding.

Chronic synovitis should be treated with intensive factor VIII
replacement plus conservative orthopaedic and physical therapy measures,
a program that produces a medical synovectomy in about one-half of the
treated joints. 36 Surgical synovectomy has been suggested for patients
with nonhealing chronic synovitis or with frequently recurring
hemarthrosis and the progressive development of severe chronic
arthropathy; it has also been successful in preventing long-term
sequelae. 37 Surgical synovectomy is associated not only with a marked
decrease in the frequency of hemorrhage in the joint, but also with some
loss of joint motion, which may not be fully regained despite physical
therapy. More recently, radioactive synovectomies, performed by
injecting radioactive dysprosium into a joint, have been done
successfully. Such a procedure can be considered for patients who are
poor surgical risks.

Joint replacement has been performed with excellent results for advanced
hip arthropathy. MLID89209501  38 Although total knee replacements have
now been performed in many patients, orthopaedists have generally
restricted this procedure to patients with such severe knee pain that
fusion is the only alternative (Fig. 106-11). Other joint prosthesis
procedures, such as total shoulder replacements, are also successfully
performed in persons with hemophilia.

Dental care should begin with preventive dentistry early in life to
minimize expense and subsequent morbidity. Restorative dentistry can now
be performed with adequate local anesthesia, including the use of
mandibular block, under coverage of factor VIII replacement.
MLID78172062  39 For oral surgery, the use of fibrinolysis inhibitors
such as e-aminocaproic acid or tranexamic acid markedly reduces the
amount of coagulation factor replacement needed for hemostasis.
MLID78172062  39 When e-aminocaproic acid is given orally at full
therapeutic doses for 710 days, a single factor VIII infusion of 40
U/kg just prior to the oral surgery is often sufficient for normal
hemostasis. If persistent, severe oozing occurs, another factor VIII
infusion may be needed.

Therapy for Mild Hemophilia A

Patients with mild hemophilia A (factor VIII levels >5%) do not bleed
spontaneously, but usually only after trauma or surgical procedures. The
current treatment of choice for patients with factor VIII levels >10% is
DDAVP (Stimate), a synthetic analogue of vasopressin. MLID89027065  40
Although its exact mechanism of action is not understood, it is thought
to stimulate release of factor VIII from storage sites. MLID81134059  41
The routine dosage is 0.3 ug/kg in 50 ml of normal saline given
intravenously over a period of 3040 minutes. In a factor VIII-deficient
patient, DDAVP will usually increase the factor VIII level threefold. 42
Thus, it may not be helpful in patients with factor VIII levels of <10%.

In order to assess how an individual patient will respond to DDAVP, a
staging test should be done. When the patient is not bleeding, a
baseline factor VIII level is obtained and then the dose of DDAVP is
administered. Thirty to 45 minutes after the infusion stops, a second
factor VIII level is checked. The factor VIII level should rise at least
threefold. If the levels rise to >80%, the response is adequate for
major surgery. In some patients DDAVP can only be used for minor
hemorrhages since the factor VIII levels do not rise sufficiently. DDAVP
can also be used with factor concentrate in mild hemophiliacs to obtain
high levels of factor VIII if needed. When DDAVP is used for major
surgery, it should be given 1 hour before surgery and then every 12
hours. Tachyphylaxis may occur after repeated doses secondary to
depletion of factor VIII from storage sites. MLID89027065  40 Thus
factor VIII levels should be checked frequently after the first 2 days.
If tachyphylaxis does occur, factor concentrate must be substituted.

If a patient with mild hemophilia has an inadequate response to DDAVP,
cryoprecipitate or factor concentrate must be used when the patient has
surgery or encounters trauma. Since plasma-derived concentrates undergo
effective virucidal procedures while cryoprecipitate cannot (and
recombinant concentrate is now available), the use of factor
concentrates is recommended.

Although DDAVP is usually administered in a hospital or emergency room
setting, a protocol can be adapted for home use. Equivalent results with
subcutaneous DDAVP can be obtained, which would make home therapy much
simpler. MLID88178538  43 Unfortunately, no subcutaneous preparation of
DDAVP is available in the United States. Intranasal DDAVP in
formulations concentrated enough to increase factor VIII levels as
efficaciously as intravenous DDAVP is now available, making home
management simpler.

The common side effects of DDAVP include facial warmth and flushing
during the infusion. Insignificant variations in blood pressure may be
noted. Headaches may occur as late as 68 hours after the infusion.
Abdominal cramping with diarrhea and generalized myalgias have rarely
been noted. In very ill patients, fluid retention resulting in
congestive heart failure has been reported. MLID85223521  44 In small
children receiving large fluid volumes, seizures induced by severe
hyponatremia after DDAVP infusion have recently occurred. MLID90053541 
45 In the young pediatric age group serum sodium levels should be
monitored and large amounts of intravenous fluid avoided if DDAVP is
used, especially if repeated doses are given. Myocardial infarction
temporally related to DDAVP infusion has been reported, MLID88094560  46
although whether DDAVP truly causes a hypercoagulable state is unclear.
These serious side effects are very uncommon. In summary, DDAVP is the
treatment of choice in persons with mild hemophilia A if they respond

Surgery And Hemophilia

Both elective and emergency surgery can be done in  a patient with
hemophilia A unless an inhibitor is present.  Before surgery (1) a
hematologist and diagnostic  coagulation laboratory should be available;
(2) the surgeon  should feel comfortable handling a patient with a 
coagulation disorder; (3) there should be a blood bank or  pharmacy
capable of providing adequate amounts of the  appropriate replacement
material; (4) an appropriate  rehabilitation team should be available
for postoperative  management, especially with orthopaedic surgery; and 
(5) no inhibitor should be present. An inhibitor level  must be checked
immediately prior to surgery. Surgery  should be scheduled on Monday or
Tuesday to allow for  availability of laboratory services for factor
level assays  and best access to consultants.

Preoperative orders should include No IM  medication and No
ASA-containing compounds such as  Darvon, Empirin or percodan. For
major surgery, the factor  VIII level should be brought to the 80 - 100%
range (4050  U/kg) about 1 hour prior to surgery and then kept  >3050%
for 1014 days. The theoretical calculations  should be checked every
23 days with factor VIII assays  and the dose adjusted accordingly.

Postoperatively, pain management should be  aggressive, with
patient-assisted narcotic delivery systems  (PCA) or constant infusional
narcotic dosing.

For oral surgery such as impacted wisdom teeth  removal, the factor
level prior to surgery is raised to 100%  with infusions.
Postoperatively e-aminocaproic acid (1 g  PO every 4 hours) for 710
days is given. If the dental  procedure is minor, e-aminocaproic acid
may be used  alone.

Patients with mild hemophilia may be able to utilize  DDAVP. If there is
a poor response to DDAVP, some  physicians use cryoprecipitate. However,
if DDABP cannot be  used, we recommend factor concentrate since it can
be  treated with viricidal methods and is thus currently safer  than

Complications of factor use include hepatitis C, which  has largely been
eliminated by the new production  methods and hemolysis due to anti-A or
anti-B in the  concentrate preparation. If hemolysis occurs, blood loss
should  be replaced by type O packed red cells, and concentrates  with
low isoagglutinin titers should be obtained and  utilized.

Health Care Delivery

The keystone of therapy in hemophilia is to provide the patient with
access to immediate and adequate correction of the hemostatic defect at
the earliest symptom suggestive of hemorrhage. For most persons with
severe and moderately severe hemophilia, the achievement of this goal is
through a combination of intensive education of the patient and family,
plus the institution of a carefully supervised self-therapy program.

Self-Therapy Program

With the exception of patients with inhibitor antibodies, those who are
unreliable or unstable, or children <3 years of age, most patients are
candidates for home therapy. The day-to-day supervision of the patient
may often be provided by a physician in the patient's immediate
geographic vicinity, with subsequent regular visits to a hemophilia
center for long-term evaluation and comprehensive care. At most centers,
all patients and selected family members receive an individual half-day
course on the pathophysiology, diagnosis, and therapy of hemophilia. The
first several infusions are administered under medical supervision. If
the patient or family demonstrate both proficiency in self-infusion and
good grasp of basic principles, maximum independence is allowed.

At some centers, all patients attend biannual comprehensive evaluation
sessions as a minimum mandatory requirement for continuation in the
program. At each session the patient is evaluated by a hematologist and
an orthopaedic surgeon, a nurse, a medical social worker, an oral
surgeon, a physical therapist, a vocational counselor, and, when
indicated, a genetic counselor and/or a psychologist or psychiatrist.
Table 106-1 Table 106-1 shows data collected on hemophiliacs treated in
traditional outpatient hematology clinics for 1 year and then introduced
into the formal comprehensive care program, which includes self-therapy.
MLID84200752  47 It should be emphasized that the least important aspect
of self-therapy is the teaching of venipuncture. The program achieves
its dramatic results through patient education as well as the systematic
application of the skills of a variety of appropriate medical personnel
who can address the long-term problems of this lifelong disease.

Because of the many problems arising from the introduction of HIV into
the blood supply in the 1970s and early 1980s, 15 comprehensive
hemophilia care now also involves dealing with the acquired
immunodeficiency syndrome (AIDS) and HIV. 48 Patients are examined at
more frequent intervals, prophylaxis with antiretroviral agents such as
zidovudine is considered, and infectious disease consultation may be
obtained. Additionally, intensive counseling sessions with the patient,
the family, and a social worker are provided for discussion of issues
such as transmission of HIV and the impact of this infection on the life
of the patient.

Complications of Therapy

Lyophilized factor concentrates revolutionized the care of persons with
hemophilia. Home therapy programs were instituted and thus the long-term
effects of hemorrhage were decreased and days lost from work or school
lessened. MLID84200752  47 Life span gradually increased until the AIDS
era. 9 Lyophilized concentrate is a pooled product made from plasma of
between 2,000 and 30,000 donors. Infectious complications from
transfusion-transmitted viruses began to be noted in hemophiliacs in the
late 1970s and subsequently became a major concern. MLID82159302  49
However, all factor concentrates currently produced are virally
inactivated, and thus infectious complications have been greatly
decreased. Increased purity of concentrates has also occurred over the
ensuing years.

Infectious Complications


The major hepatitis viruses transmitted through plasma-derived
concentrate and cryoprecipitate infusion are hepatitis B (HBV) and C
(HCV). Acute HBV infection with elevated liver function tests, jaundice,
and fever is uncommon in hemophiliacs, but approximately 90% of patients
who were given infused concentrates before the current viral
inactivation methods became available have developed antibody to HBV
(HBsAb positive), indicating exposure. MLID85155884  50 A small
percentage of patients, approximately 5%, have become chronic carriers
(HBsAg positive). 51 Chronic carriers may be more prone to the
development of symptomatic chronic liver disease or carcinoma of the
liver. Delta hepatitis (HDV), a virus that requires the presence of HBV
as a carrier, is also a potential risk to hemophilia patients,
especially in endemic areas, since coinfection with HDV and HBV may
cause fulminant hepatitis. MLID85155884  50 Persons with hemophilia who
are chronic HBV carriers may also have antibodies to HDV, indicating
exposure to HDV through factor concentrate. Even with virucidal methods
used currently to prepare factor concentrate, HBV infections have been
reported. Thus, all newly diagnosed persons with hemophilia should
receive HBV vaccination. In a newly diagnosed infant, the series of
three innoculations is started at birth.

HCV has been a common infectious complication of factor infusion. (It
was termed non-A, non-B hepatitis in the 1970s. MLID77202197  52) A
serologic marker for HCV is available. MLID89222454 MLID89222455  53,54
Data suggest that E80% of persons with hemophilia infused before 1985
carry the marker, indicating past exposure to the virus. Approximately
90% of hemophiliacs have either persistently or intermittently elevated
liver enzymes, which most likely represents the consequences of HCV
exposure. 55 When liver biopsies are done on selected hemophilia
patients with abnormal liver enzymes, 20%30% have shown changes
consistent with chronic active hepatitis or cirrhosis. MLID85253208  56
HCV has also been associated with the development of heptacellular
carcinoma. MLID91314600  57 Thus, HCV may represent a long-term problem
for persons with hemophilia.

Outbreaks of hepatitis A related to factor concentrate have recently
been reported from Europe. As a vaccine for hepatitis A becomes
available, newly diagnosed persons with hemophilia should receive it.

Human Immunodeficiency Virus

HIV was introduced into the American blood supply in the 1970s. 58 By
the late 1970s, factor concentrate was widely contaminated and by 1982,
approximately 50% of persons with hemophilia were infected with HIV. 59
Currently, 70% of American hemophiliacs are HIV antibody positive. 60
Hemophilic patients, especially those infected after the age of 22 years
and those who have been HIV seropositive for at least 7 years, have
approximately 40% probability of developing symptomatic AIDS.
MLID87239713  61 It is not clear why the age of acquisition of infection
should influence outcome, but this has now been confirmed in a larger
multicenter study. MLID90015005  62 Otherwise, when compared with other
high-risk groups, the course of HIV-1 infection in hemophilia is very
similar. As in other risk groups, low CD4 lymphocyte levels are strong
predictors of which specific person will become symptomatic.
Pneumocystis carinii pneumonia (Fig. 106-12) was the most common
presenting AIDS-defining condition in HIV-seropositive hemophilia
patients before the advent of prophylaxis. Other opportunistic
infections, such as candida esophagitis and cryptococcal
meningitis/septicemia, are reported in this subgroup. Kaposi sarcoma,
however, is a very rare presenting condition in persons with hemophilia.
Non-Hodgkin lymphoma can occur late in the disease at an incidence of
5.5%. MLID93214045  63

Currently, as with other HIV-seropositive patients, persons with
hemophilia who have CD4 lymphocyte counts <400500 cells/ml can be
considered for prophylactic zidovudine; in those with a count of <200
cells/mm3, Pneumocystis prophylaxis should be added. The use of
antiretroviral drugs that are hepatotoxic may be more problematic in
persons with hemophilia since many have pre-existing liver disease
secondary to HCV. Thus, liver chemistries should be monitored carefully,
especially in persons on combination antiretroviral therapy.

Virucidal Treatments of Concentrates

There is now a triple barrier to viral transmission through factor
concentrates: (1) self-exclusion for donors, (2) donor screening, and
(3) viral inactivation procedures. Self-exclusion includes asking the
plasma donor detailed questions concerning hepatitis, possible HIV
exposure, and general health (to elicit nonspecific symptoms of HIV
infection). Donor screening now includes HCV testing, as well as
serologic testing for HIV-1 and HBV.

Multiple methodologies for attenuating viruses during processing of
factor concentrate have been devised. MLID89274385  64 They include
heating the concentrate and the use of solvent/detergent combinations,
which disrupt lipid-coated viruses such as HIV and some hepatitis
viruses. MLID94054272  65,66

A third methodology for eliminating virus from concentrate involves
affinity chromatography using a murine monoclonal antibody to either von
Willebrand factor or factor VIII. MLID88264483  67 Cryoprecipitate is
used as the starting material. A much higher purity factor VIII
concentrate results (specific activity >3,000 U/mg protein before
addition of albumin stabilizer). HIV titers are reduced significantly by
this process. The product is either pasteurized in the final stage
(Monoclate-P, Rorer) or is initially treated with tri-n-butyl phosphate
(TNBP)/Triton X-100 (Hemophil M, Hyland). A summary of these methods and
specific concentrates is given in Table 106-2 Table 106-2.

Alloantigens in Factor Concentrate

In addition to viral contamination of factor concentrates, it has been
shown (beginning in the early 1980s) that intermediate purity
concentrate itself may cause immune aberrations in hemophiliacs, perhaps
secondary to the presence of multiple foreign proteins. MLID84244712  68
Factor concentrate in vitro may down-regulate Fc receptors on the
macrophage MLID87158064  69 or may inhibit the mixed lymphocyte culture
reaction MLID88264484  70 or interleukin-2 production by monocytes.
MLID89194118  71 Since detailed immunologic studies were not done
routinely on the hemophilia population before infection of patients with
HIV, information regarding the effect of concentrate on patients is
sporadic. In Scotland, in a group of HIV-seronegative hemophiliacs
receiving locally produced factor concentrate not contaminated by HIV,
approximately 50% demonstrated mildly decreased helper/suppressor
T-lymphocyte ratios secondary to depressed CD4 cell levels. MLID84244712
 68 These abnormalities appeared to be related to intensity of
treatment. Others researchers have also shown that in a group of
HIV-seronegative hemophiliacs, CD4 cell levels are mildly reduced when
compared with normal controls. 72 Thus, frequent infusions of
intermediate purity factor concentrates may lead to mild immune

Additional Complications

Other complications of treatment with concentrate include urticaria,
temperature elevations, and very rarely anaphylaxis. Urticaria and
bronchospasm are more commonly seen with infusions of cryoprecipitate.
When cryoprecipitate is used, some centers order type-specific products.

Factor concentrates may also contain measurable titers of isoagglutinins
(anti-A or anti-B). When concentrate is administered in large amounts,
such as postoperatively, to patients with A and B blood types,
significant hemolysis may occur. MLID72211952  73 If the patient with
this complication requires blood transfusions, type O should be given.
Factor concentrate with low isoagglutinin titer can subsequently be
obtained from specific manufacturers. Rarer complications of factor
concentrate include a syndrome of primary pulmonary hypertension
described in five patients with severe hemophilia A who used large
amounts of concentrate. MLID88220869  74 The mechanism has not been
elaborated but may be due to particulate matter or immune complexes
being deposited in the lungs. A summary of infectious implications
associated with therapy is given in Table 106-3 Table 106-3.

Choice of Concentrate

Selection of a factor concentrate depends on efficacy, safety concerning
virally transmitted diseases, purity, and cost. Demonstrating that a
concentrate is free of harmful viruses is difficult since reliable
animal models, especially for HCV, are not available. Human clinical
trials are necessary to prove that new factor concentrates are safe. To
demonstrate whether a specific concentrate is free of HBV, HCV, or HIV,
studies using previously nontransfused patients, primarily newly
diagnosed hemophiliac infants, are undertaken. Serologic studies of
antiviral antibodies and liver function may be positive if patients are
exposed to specific viruses.

Both HCV and HBV are difficult to inactivate. Heating the lyophilized
concentrate at 6068C for 3072 hours does not inactivate HCV, although
raising the temperature to 80C for 72 hours does eliminate HCV.
MLID94054272  66 Heating the concentrate in solution (60C for 10 hours
of "pasteurization") appears to kill HCV, although there are anecdotal
reports that hepatitis B and C have still occurred after pasteurization
methods were used. MLID87144520 MLID89013554  75,76

Solvent/detergent-treated concentrates appear to be free of HCV.
MLID88287648  77 Of note is that solvent/detergent methods do not
inactivate viruses without lipid envelopes. Thus, parvovirus, for
example, may not be killed. In Ireland, Italy, Germany, and Belgium a
recent outbreak of hepatitis A occurred in 84 hemophilia patients
infused exclusively with solvent/detergent-inactivated concentrates
purified by ion exchange chromatography. MLID92194930  78

HIV appears to be easily inactivated by any of the current viral
inactivation procedures. In all viral safety trials in which HIV
antibody status was studied, which include over 300 subjects, no
seroconversions occurred. MLID89274385  64 However, 18 cases of HIV
seroconversion have been reported with heat-treated factor VIII
concentrate not associated with viral safety trials. 79 Most cases used
concentrate that was dry heated at 60C, a methodology that is no longer
used. "Dry heat" at high temperatures for longer periods of time (80
for 72 hours), vapor treatment, or heat treatment in solution
("pasteurization") appear to be efficacious in killing HIV. The
solvent/detergent methods, as well as purification by affinity
chromatography, also appear safe, vis--vis HIV infection.

Purity of Factor VIII 

It is our opinion that for previously untreated and  infrequently
treated hemophiliacs and for others who are free  of HIV infection, a
concentrate that is pasteurized,  treated with solvent/detergent, or
immunoaffinity  purified can be used. It should be virus free, but not 
necessarily highly purified. For HIV-seropositive patients, highly 
purified concentrates that are virally inactivated offer  theoretical

Highly Purified Concentrate

Concentrates purified using affinity chromatography (Monoclate, Hemophil
M) have a final specific factor VIII activity of approximately 3,000
U/mg protein. MLID88264483  67 The purity is significantly higher than
previously available products, and most extraneous human proteins have
been removed. These products are efficacious and appear to be free of
hepatitis viruses and HIV.

Since extraneous proteins such as immune complexes, aggregated
immunoglobulins, and the killed viruses may be additionally suppressive
to the immune system of a hemophiliac, concentrates containing only
factor VIII and albumin may be less immunosuppressive. This would
theoretically be beneficial not only to previously untransfused
patients, but to HIV-seropositive patients as well.

An early nonrandomized study of 14 HIV-1-seropositive patients compared
the initial seven patients on high-purity factor VIII concentrate with
seven patients on intermediate-purity concentrate (specific activity 13
U/mg protein); in the first group CD4 cell counts stabilized over the
3-year course of the study, while the second group had a decrease in CD4
counts. MLID89229428  80 There are now three randomized prospective
trials comparing the effects of intermediate-purity versus high-purity
concentrates on the immune system of HIV-1 seropositive hemophiliacs. 81
Two studies, using immune affinity-purified factor VIII, have shown
independently that HIV-1-seropositive hemophilia patients have a slower
decline of CD4 cell counts on the very high-purity concentrate versus
the intermediate-purity concentrate. 82,83 In a third study using a less
high-purity concentrate, no difference between the two groups could be
seen. MLID92351359  84 All studies were performed with small numbers of

Recombinant Factor VIII

Currently, there are three recombinant factor VIII products approved for
clinical use, Recombinate (Baxter), Kogenate (Miles), and Bioclate
(Armour). The final products are highly purified factor VIII, with a
specific activity of approximately 7,000 U/mg protein prior to the
addition of human albumin. Recombinant factor VIII has been shown to be
safe and as efficacious as plasma-derived factor VIII concentrate, with
similar recovery and half-life. MLID91061845  13,14,85 Major surgery has
been performed using the concentrate, with excellent hemostasis.

Two ongoing clinical trials are evaluating inhibitor development in
persons with hemophilia treated with recombinant factor VIII. The
patients in these trials are those most at risk of inhibitor
development: persons who have previously been untransfused, mostly
infants. To date, 16 of 64 patients developed an inhibitor after a
median of 9 exposure days. MLID93133254  86 Although this prevalence is
high, in 9 of the 16 patients, inhibitors remained at low titer. In
another study, 17 of 69 previously untransfused patients given
recombinate by infusion developed inhibitors. MLID94220686  87 It is not
clear whether recombinant factor concentrate leads to increased
inhibitor development or inhibitor development at an earlier time.
Previous studies showing inhibitor prevalences of 1015% were
cross-sectional cohort, not prospective studies in a high-risk group.
Also, the patients were not monitored as closely for inhibitor
development. Thus, these studies are difficult to compare.

Factor VIII: Recombinant Versus Plasma Derived 

Who should receive recombinant factor concentrate?  There are many
different opinions; ours is that this  product should be reserved for
those persons with  hemophilia who are HIV-1 seronegative as well as HCV
 seronegative (i.e., mostly young children). The product is  E$0.10/unit
more expensive than the most expensive  plasma-derived high-purity
product. In this era of  medical cost containment, price is a large
issue. In addition,  the possibility of inhibitor development must be 
discussed with the family or patient who will receive  recombinant
factor VIII.

Cure of Hemophilia A

Liver transplantation currently offers a cure for hemophilia, albeit an
impractical one. Persons with hemophilia A have undergone liver
transplantation because of end-stage liver disease caused by HBV or HCV.
In one of the first series (four patients with hemophilia A), three
survived the initial surgery and then normalized their factor VIII
levels, requiring no further replacement. MLID87214539  88 Additional
patients with hemophilia A have since undergone liver transplantation;
of those who survived, factor VIII levels have been normalized. In the
future, gene replacement therapy may offer a hope of cure to all persons
with hemophilia.

Genetic Counseling and Prenatal Diagnosis

The cloning of the factor VIII gene and the determination of its
molecular structure allow detection of carriers and accurate prenatal
diagnosis. Female relatives of individuals with hemophilia may be
carriers of the abnormal gene, and therefore may be at risk of having
children with hemophilia. Women who are considered obligate carriers are
daughters of individuals with hemophilia and women who have one son and
another relative with hemophilia. These women have a 50% risk of each
newborn son having hemophilia. Women who have two sons with hemophilia
are obligate heterozygotes. However, a small proportion of these women
may be either somatic mosaics or germline mosaics. MLID90368079  89
Reproductive risk in these circumstances is difficult to assess and
depends on the proportion of ova carrying the abnormal gene.

Other female relatives are considered possible carriers of the gene for
hemophilia. This would include women who have one son with hemophilia
and no other affected relatives. In these isolated cases, the hemophilia
may result from (1) transmission through asymptomatic females, (2) a new
mutation in the mother, (3) a new mutation in the individual with
hemophilia (a true de novo mutation), or (4) as a result of somatic or
germline mosaicism in the mother. MLID89126635  90 The probability for
carriership for a mother of an isolated case is estimated to be 0.85.
MLID93271395  91

Carrier Detection

Potential hemophilia A carriers should be offered genetic testing for
determination of carrier status. Current methods of carrier detection
include standard phenotypic clotting assays, as well as more accurate
genotypic analysis. Probability of carriership should first be
determined from pedigree data. Information anterior to the proband is
used to determine genetic risk. This figure can be modified by Bayesean
analysis if the individual has any sons without hemophilia.

Phenotypic assessment of carrier status for hemophilia A is determined
by specific assays for factor VIII activity, factor VIII antigen, and
von Willebrand factor antigen. In general, women who are carriers of
hemophilia A have approximately 50% of the normal level of factor VIII.
These values may be affected by various physiologic conditions or
medications, or both. Of particular note are the effect of pregnancy
(especially after the 22nd week of gestation) and estrogen-containing
drugs such as birth control pills, which elevate factor VIII levels.
MLID83049576 MLID75189904  92,93 The age of the individual being tested
and the ABO blood type must also be noted; blood type O is associated
with decreased factor VIII levels. MLID86216617  94 Factor VIII
concentrations are also influenced by X-chromosome inactivation (the
Lyon hypothesis), which may cause false-negative results. 95 Laboratory
data are used to determine probability of carriership. The laboratory
values can be combined with the pedigree data to give a final
probability. For determination of odds ratios favoring carriership in
hemophilia A, bivariate linear discriminant analysis using factor VIII,
von Willebrand antigen, age, and ABO blood type is recommended.

Determination of carrier status for hemophilia A may also be performed
using molecular diagnostic methods. The factor VIII gene is large (see
Ch. 105), and the mutations identified to date are heterogeneous. Thus,
direct mutational analysis is not available for routine screening. Most
genotypic testing employs an indirect marker, restriction fragment
length polymorphism (RFLP). Which marker to use for polymorphism
analysis is determined by the mutation's location (intragenic versus
extragenic), the degree of heterozygosity, and the ethnic origin of the
family. Southern blot analysis and polymerase chain reaction are the
techniques used for identification of these polymorphisms. For
hemophilia A, >95% of females are informative, with the following
intragenic markers: the intron 13 CA repeat, the intron 22 CA repeat,
BclI, and XbaI. The BglI and the intron 7 polymorphism may be
informative in other families. Indirect testing using intragenic markers
is >99% accurate. However, there are limitations. For the study to be
informative, the marker must be heterozygous. Heterozygosity differs
significantly in various ethnic groups, and this must be accounted for
when considering which polymorphisms to use in a particular family.
Blood samples from several key family members are required for genotypic
testing. Blood from an affected male is required. Since many older
hemophiliacs are infected with HIV-1 and thus have shortened survival,
blood sampling to obtain DNA that can then be frozen for future use in
genetic analysis should be encouraged. All family members must agree to
genotypic testing, and all family relationships reported must be
correct. In some families linked extragenic markers may be informative,
but accuracy of the results is decreased due to possible genetic

When sporadic cases of hemophilia occur in a family, polymorphism
testing can only be used to exclude transmission of the mutation because
the mutation is not identified by these methods, and therefore its
origin is not known. In these families, direct mutation analysis can be
considered. Direct screening methods for mutations in these large genes
have been developed. Three screening methods are utilized for hemophilia
A: denaturing gradient gel electrophoresis, single-stranded
conformational polymorphism analysis, and direct sequencing of amplified
DNA. MLID90169988 MLID89323457 MLID90152691 MLID94100976  96100

Prenatal Diagnosis

Several techniques are available for the prenatal diagnosis of
hemophilia. The basic strategy is to determine fetal sex first, and then
to determine whether the fetus has the gene for hemophilia. Fetal sex
can be determined by ultrasonography and fetal chromosome analysis.
Experienced sonographers can determine fetal sex reliably at 1620 weeks
of gestation. Fetal sex, however, is more accurately determined by
examination of the fetal chromosomes. Chromosomes can be obtained by
amniocentesis or chorionic villus sampling (CVS). Amniocentesis is
performed at 1520 weeks' gestation or at 1214 weeks' gestation ("early
amniocentesis"risk approximately 1%). MLID92373696  101,102 CVS, by
either the transcervical or the transabdominal route, is done at 912
weeks' gestation. MLID89143658 MLID92350194  103,104 In general, whether
amniocentesis or a CVS procedure is chosen depends on patient
preferences regarding timing of the procedure, risk to the fetus, and
reliability of the results. Reports suggesting an association between
CVS and limb reduction defects have raised questions about the risks of
this procedure. These risks can be lessened if the CVS procedure is
performed after 10 weeks' gestation, and if placental trauma is
minimized. The risk of loss of pregnancy may be somewhat higher for CVS
compared with amniocentesis.

The diagnosis of hemophilia in a fetus can be accomplished by genotypic
analysis of fetal DNA or by phenotypic analysis of fetal blood. Fetal
DNA can be extracted from both fetal amniocytes and chorionic villi and
analyzed by RFLP of the DNA, as above. If prenatal diagnosis is not
possible by DNA analysis, then fetal blood sampling can be done by a
cordocentesis. This technique is done from 2021 weeks' gestation and
involves the ultrasound-guided puncture of an umbilical cord vessel.
MLID86047995  105 The fetal blood is analyzed by phenotypic clotting

Preimplantation diagnosis after in vitro fertilization has recently been
proposed as a method of prenatal testing. Amplification of informative
regions of the factor VIII gene by polymerase chain reaction from a
single cell has been reported. All women who undergo carrier testing or
prenatal diagnosis, or both, for hemophilia should have genetic
counseling, preferably before choices regarding carrier testing and
prenatal diagnosis must be made. The aims of counseling in these cases
are to provide information about genetic risk, determination of carrier
status, and prenatal diagnosis as well as to provide psychological and
emotional support during the processes.